Authorities say a 14-year-old died in the crash and, in the video, she references the victim as her sister. The CHP says two minors were in the back seat were not wearing seatbelts.
The CHP says Sanchez was under the influence when she rolled her car over, into a barbed wire fence and then a field. The Merced County Sheriff says 14-year-old Jacqueline Sanchez was killed in the crash near Henry Miller Road and Highway 165.
"She was in the back seat of the vehicle and allegedly unseatbelted, and upon the vehicle rolling over, it ejected her and killed her," Sheriff Vern Warnke said.
"I killed my sister, but I don't care," she said in the video. "I killed my sister. I know I'm going to prison, but I don't care. I'm sorry baby. I'm a hold it down."
Mary Hernandez of Stockton recorded the live stream.
"At first we didn't even want to believe it was real," she said. "I recorded it and posted it mainly because as someone who uses Snapchat I see a lot of people driving with their Snapchats doing what she was doing so to me it was like an eye opener."
Family members confirm the video was shot by Obdulia Sanchez. They say the victim, Jacqueline Sanchez of Stockton, was supposed to celebrate her Quinceanera Sunday.
A 14-year-old girl from Fresno was also in the car and was badly injured.
Sanchez is now in the Merced County Jail on charges of vehicular manslaughter while under the influence and DUI.